Conjugated polymers having as a repeating unit a structure containing a 5-membered heterocyclic ring are important as organic electronic materials. Among them, polymers having a high proportion of head to tail structure (hereinafter, referred to as “HT structure”) in which the orientation of the bonds of a repeating unit are constant (hereinafter, referred to as “HT regioregular”) are called “HT regioregular polymer”. HT regioregular polymers are known to have high electric conductivity since flatness is higher and conjugation length is longer as compared with regiorandom polymers having a small proportion of HT structure. For example, there is suggested a HT regioregular polythiophene in which the orientation of a repeating unit is fixed at the bond position of a side chain substituent (Polymer Journal, vol. 6, p. 65 (2004)).
However, HT regioregular polymers having as a repeating unit a 5-membered ring of asymmetric ring structure are scarcely known. For example, a HT regioregular oligomer of oxazole is suggested (JP-A No. 2005-223238).
However, oligomers are believed to have poor practical utility.
Then, there is desired a compound with which a HT regioregular polymer can be synthesized having a high proportion of a HT structure having as a repeating unit a 5-membered ring of asymmetric ring structure.
Thus, the present invention has an object of providing a compound with which a HT regioregular polymer can be synthesized having as a repeating unit a 5-membered ring of asymmetric ring structure and having a high proportion of HT structure.
The present inventors have intensively studied to accomplish the above-described object and resultantly found a novel heterocyclic compound, and finally have completed the present inventions.